Cooper

The bridge is immense, not only in length and weight but in width. At 67 feet wide, it can accommodate two sets of railway tracks, two sets of streetcar tracks and two roadways.

It took three tries and cost 89 lives, but the city of Quebec was determined to compete with provincial rival Montreal for commercial rail traffic in the late 19th century. The solution was a rail bridge across the St. Lawrence River requiring a single cantilever span 1,800 feet long - the longest ever attempted. 

Spearheaded by Hugh Cooper, the Keokuk Dam & Power Plant served as a prototype for many future power plants. The project harnessed the hydropower of the Mississippi River, between Keokuk, Iowa and Hamilton, Illinois.

The crest of the dam is nearly a mile long. The dam structure features 119 arch spans between six-foot-thick piers and a 110-foot-wide pneumatic lock. Combined with the lock, the dam reduced travel time for steamboats by nearly two hours.